Gullfaks is a typical mature field where cost efficient solutions need to be in focus. There is also the challenge that old wells produce at low rates, but nevertheless at rates not drastically lower than those that an alternative use of the slot can deliver. One solution to this challenge is to maintain production from the old well while simultaneously gaining inexpensive access to new a drainage point(s).
B-1A on the Gullfaks field was drilled and completed in January 2003 using hollow whipstock technology. The operation was a technical success which proved that Multilateral (MLT) solutions can be delivered at costs only marginally above those of a conventional sidetrack. To further enhance the value of the slot, a second through tubing MLT lateral was added in January 2005.
The key considerations during the planning phase were proven solutions, cheap technology and low risk. This paper illustrates the decision process prior to choosing this particular technology, the installation process itself, the lessons learned and the strategy which may be applied in the future.